Are Health Apps and Gadgets accurate?

Apps on Google Play: Top Free in Health & Fitness
Apps on Google Play: Top Free in Health & Fitness

I was planning to write up a review of various health apps and gadgets, in fact, I was also thinking of developing an “app” for MotleyHealth. However, I have just read an article in TechCrunch which suggests that many apps are not very reliable.

TechCrunch article: If Inaccuracy Were Illegal, The Feds Would Have To Regulate Most Health Gadgets

Gregory Ferenstein’s title sums up his conclusions pretty well – it certainly made me want to read. It seems he was prompted to investigate after a BodyMedia armband he was wearing reported that he was burning 3000 Calories a day – enough to burn off all the food he had eaten and breakdown most of his muscle and fat tissue.

We all know the no two sets of scales ever seem to give the same result, so why do we all quickly trust gadgets and apps?

Gregory tested several popular gadgets and found that the readings given by his Basis watch, Nike FuelBand, Jawbone UP, BodyMedia, and Fitbit gadgets differed by over 1000 Calories in a day. This is an error of 7000 Calories over a week, which could be the difference between gaining one pound of fat and losing one pound of fat. No wonder so many people fail to lose weight – their apps are telling them that their workout is complete when it is not!

Both Yahoo and the New York Times have reported similar problems. An error of 1000 Calories is huge; it is the difference between losing and gaining weight.

“If you are basing what you eat on these devices, and they are overestimating the calories you burned, you may not have actually earned that extra candy bar. Can you say, weight gain?” Becky Worley, Yahoo!

Smartphone Apps

iTunes health apps
iTunes health apps

The apps market is huge now. There are thousands of Android and iPhone health apps on the market, plus a huge array of specialist gadgets including pedometers, motion sensors, blood pressure readers, heart rate monitors and currently a growing number of fitness bracelets and ankle bands.

Most modern health gadgets are designed to connect to smartphones via Bluetooth. In addition to such devices there are thousands of health apps which use the various features of smartphone technology to work, such as GPS and motion sensors.

The problem is that anybody can write an app for a smartphone. For example, if you wanted to have an app custom built for your phone or to share via a website, you could visit a site such as and search for an app developer to employ.

A search for “app developer” in Elance brings up 14,022 results, with developers from all over the world. All of these are probably capable of creating an app to your specifications, but what guarantees are in place to ensure that the reports and readouts on these apps are accurate? Can you really rely on this information to optimize your fitness training or effectively modify your fat loss diet?

In the past I have tested various heart rate apps for Android and always found them to be woefully inaccurate. I eventually installed a simple timer to count seconds while I held my pulse – the most accurate way by far, which is why doctors still do this method rather than pull out their latest iPhone.

I do not know how many apps are in the Google Play store, but I scrolled through around 29 pages, each of which has 21 apps listed, so somewhere in the region of 609 apps. These are just the free ones. iTunes is similar – there are hundreds of health and fitness apps listed, many of which are no doubt extremely useful.

Many free apps are made by companies to help push their product direct to users via a smartphone. Some are made by hobbyists who then share their creation. There is no regulation in place to ensure that any of them are actually accurate.

Evidence-informed practices for weight control?

Emily R Breton and colleagues investigated the state of weight loss apps. The research was published in Translational Behavioral Medicine. They checked weight loss apps to see if they adhered to 13 evidence-informed practices for weight control.

The study found that only 15% of apps had five or more of the 13 practices in place. The research concluded that: “Many apps have insufficient evidence-informed content. Research is needed that seeks to develop, improve, and evaluate these apps.”

Stop watch and notepad

a silver stop watchFor years coaches managed to get their athletes into top shape with little more than a good watch and a notepad. Do we really need apps to manage our health and fitness goals for us?

Some apps are certainly useful. On Google Play there is Beep Test (we covered beep (bleep) tests in our article on fitness testing).

An app that is totally objective is certainly useful. Apps that attempt to measure calories burned by using motion detectors and GPS are not accurate. Diet apps also rely on the user accurately inputting what they have eaten and also knowing exactly what they eaten.

We live in a world of gadgets and apps, but how many of us really need them? How important is it to know exactly how far you ran, and then to be able to upload it to social media? Can your phone accurately record how many calories you have burned. Can we trust any of this information?

The best way to use apps is to monitor and track your actual progress; you input the distance run, time exercised, weight lifted and amount of food eaten. Then adjust your routines to improve your performance. Do not just follow what the gadgets and apps say; instead use them to provide a rough guide.


Weight loss—there is an app for that! But does it adhere to evidence-informed practices?” By Emily R Breton MPH, Bernard F Fuemmeler PhD, MPH, Lorien C Abroms ScD. Translational Behavioral Medicine Volume 1, Issue 4 , pp 523-529

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